drivers/i2c/busses/i2c-at91-core.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  i2c Support for Atmel's AT91 Two-Wire Interface (TWI)
   4  *
   5  *  Copyright (C) 2011 Weinmann Medical GmbH
   6  *  Author: Nikolaus Voss <n.voss@weinmann.de>
   7  *
   8  *  Evolved from original work by:
   9  *  Copyright (C) 2004 Rick Bronson
  10  *  Converted to 2.6 by Andrew Victor <andrew@sanpeople.com>
  11  *
  12  *  Borrowed heavily from original work by:
  13  *  Copyright (C) 2000 Philip Edelbrock <phil@stimpy.netroedge.com>
  14  */
  15
  16 #include <linux/clk.h>
  17 #include <linux/err.h>
  18 #include <linux/i2c.h>
  19 #include <linux/io.h>
  20 #include <linux/module.h>
  21 #include <linux/of.h>
  22 #include <linux/of_device.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/pm_runtime.h>
  25 #include <linux/pinctrl/consumer.h>
  26
  27 #include "i2c-at91.h"
  28
  29 unsigned at91_twi_read(struct at91_twi_dev *dev, unsigned reg)
  30 {
  31         return readl_relaxed(dev->base + reg);
  32 }
  33
  34 void at91_twi_write(struct at91_twi_dev *dev, unsigned reg, unsigned val)
  35 {
  36         writel_relaxed(val, dev->base + reg);
  37 }
  38
  39 void at91_disable_twi_interrupts(struct at91_twi_dev *dev)
  40 {
  41         at91_twi_write(dev, AT91_TWI_IDR, AT91_TWI_INT_MASK);
  42 }
  43
  44 void at91_twi_irq_save(struct at91_twi_dev *dev)
  45 {
  46         dev->imr = at91_twi_read(dev, AT91_TWI_IMR) & AT91_TWI_INT_MASK;
  47         at91_disable_twi_interrupts(dev);
  48 }
  49
  50 void at91_twi_irq_restore(struct at91_twi_dev *dev)
  51 {
  52         at91_twi_write(dev, AT91_TWI_IER, dev->imr);
  53 }
  54
  55 void at91_init_twi_bus(struct at91_twi_dev *dev)
  56 {
  57         at91_disable_twi_interrupts(dev);
  58         at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_SWRST);
  59         if (dev->slave_detected)
  60                 at91_init_twi_bus_slave(dev);
  61         else
  62                 at91_init_twi_bus_master(dev);
  63 }
  64
  65 static struct at91_twi_pdata at91rm9200_config = {
  66         .clk_max_div = 5,
  67         .clk_offset = 3,
  68         .has_unre_flag = true,
  69 };
  70
  71 static struct at91_twi_pdata at91sam9261_config = {
  72         .clk_max_div = 5,
  73         .clk_offset = 4,
  74 };
  75
  76 static struct at91_twi_pdata at91sam9260_config = {
  77         .clk_max_div = 7,
  78         .clk_offset = 4,
  79 };
  80
  81 static struct at91_twi_pdata at91sam9g20_config = {
  82         .clk_max_div = 7,
  83         .clk_offset = 4,
  84 };
  85
  86 static struct at91_twi_pdata at91sam9g10_config = {
  87         .clk_max_div = 7,
  88         .clk_offset = 4,
  89 };
  90
  91 static const struct platform_device_id at91_twi_devtypes[] = {
  92         {
  93                 .name = "i2c-at91rm9200",
  94                 .driver_data = (unsigned long) &at91rm9200_config,
  95         }, {
  96                 .name = "i2c-at91sam9261",
  97                 .driver_data = (unsigned long) &at91sam9261_config,
  98         }, {
  99                 .name = "i2c-at91sam9260",
 100                 .driver_data = (unsigned long) &at91sam9260_config,
 101         }, {
 102                 .name = "i2c-at91sam9g20",
 103                 .driver_data = (unsigned long) &at91sam9g20_config,
 104         }, {
 105                 .name = "i2c-at91sam9g10",
 106                 .driver_data = (unsigned long) &at91sam9g10_config,
 107         }, {
 108                 /* sentinel */
 109         }
 110 };
 111
 112 #if defined(CONFIG_OF)
 113 static struct at91_twi_pdata at91sam9x5_config = {
 114         .clk_max_div = 7,
 115         .clk_offset = 4,
 116 };
 117
 118 static struct at91_twi_pdata sama5d4_config = {
 119         .clk_max_div = 7,
 120         .clk_offset = 4,
 121         .has_hold_field = true,
 122         .has_dig_filtr = true,
 123 };
 124
 125 static struct at91_twi_pdata sama5d2_config = {
 126         .clk_max_div = 7,
 127         .clk_offset = 3,
 128         .has_unre_flag = true,
 129         .has_alt_cmd = true,
 130         .has_hold_field = true,
 131         .has_dig_filtr = true,
 132         .has_adv_dig_filtr = true,
 133         .has_ana_filtr = true,
 134 };
 135
 136 static struct at91_twi_pdata sam9x60_config = {
 137         .clk_max_div = 7,
 138         .clk_offset = 3,
 139         .has_unre_flag = true,
 140         .has_alt_cmd = true,
 141         .has_hold_field = true,
 142         .has_dig_filtr = true,
 143         .has_adv_dig_filtr = true,
 144         .has_ana_filtr = true,
 145 };
 146
 147 static const struct of_device_id atmel_twi_dt_ids[] = {
 148         {
 149                 .compatible = "atmel,at91rm9200-i2c",
 150                 .data = &at91rm9200_config,
 151         }, {
 152                 .compatible = "atmel,at91sam9260-i2c",
 153                 .data = &at91sam9260_config,
 154         }, {
 155                 .compatible = "atmel,at91sam9261-i2c",
 156                 .data = &at91sam9261_config,
 157         }, {
 158                 .compatible = "atmel,at91sam9g20-i2c",
 159                 .data = &at91sam9g20_config,
 160         }, {
 161                 .compatible = "atmel,at91sam9g10-i2c",
 162                 .data = &at91sam9g10_config,
 163         }, {
 164                 .compatible = "atmel,at91sam9x5-i2c",
 165                 .data = &at91sam9x5_config,
 166         }, {
 167                 .compatible = "atmel,sama5d4-i2c",
 168                 .data = &sama5d4_config,
 169         }, {
 170                 .compatible = "atmel,sama5d2-i2c",
 171                 .data = &sama5d2_config,
 172         }, {
 173                 .compatible = "microchip,sam9x60-i2c",
 174                 .data = &sam9x60_config,
 175         }, {
 176                 /* sentinel */
 177         }
 178 };
 179 MODULE_DEVICE_TABLE(of, atmel_twi_dt_ids);
 180 #endif
 181
 182 static struct at91_twi_pdata *at91_twi_get_driver_data(
 183                                         struct platform_device *pdev)
 184 {
 185         if (pdev->dev.of_node) {
 186                 const struct of_device_id *match;
 187                 match = of_match_node(atmel_twi_dt_ids, pdev->dev.of_node);
 188                 if (!match)
 189                         return NULL;
 190                 return (struct at91_twi_pdata *)match->data;
 191         }
 192         return (struct at91_twi_pdata *) platform_get_device_id(pdev)->driver_data;
 193 }
 194
 195 static int at91_twi_probe(struct platform_device *pdev)
 196 {
 197         struct at91_twi_dev *dev;
 198         struct resource *mem;
 199         int rc;
 200         u32 phy_addr;
 201
 202         dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
 203         if (!dev)
 204                 return -ENOMEM;
 205
 206         dev->dev = &pdev->dev;
 207
 208         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 209         if (!mem)
 210                 return -ENODEV;
 211         phy_addr = mem->start;
 212
 213         dev->pdata = at91_twi_get_driver_data(pdev);
 214         if (!dev->pdata)
 215                 return -ENODEV;
 216
 217         dev->base = devm_ioremap_resource(&pdev->dev, mem);
 218         if (IS_ERR(dev->base))
 219                 return PTR_ERR(dev->base);
 220
 221         dev->irq = platform_get_irq(pdev, 0);
 222         if (dev->irq < 0)
 223                 return dev->irq;
 224
 225         platform_set_drvdata(pdev, dev);
 226
 227         dev->clk = devm_clk_get(dev->dev, NULL);
 228         if (IS_ERR(dev->clk)) {
 229                 dev_err(dev->dev, "no clock defined\n");
 230                 return -ENODEV;
 231         }
 232         clk_prepare_enable(dev->clk);
 233
 234         snprintf(dev->adapter.name, sizeof(dev->adapter.name), "AT91");
 235         i2c_set_adapdata(&dev->adapter, dev);
 236         dev->adapter.owner = THIS_MODULE;
 237         dev->adapter.class = I2C_CLASS_DEPRECATED;
 238         dev->adapter.dev.parent = dev->dev;
 239         dev->adapter.nr = pdev->id;
 240         dev->adapter.timeout = AT91_I2C_TIMEOUT;
 241         dev->adapter.dev.of_node = pdev->dev.of_node;
 242
 243         dev->slave_detected = i2c_detect_slave_mode(&pdev->dev);
 244
 245         if (dev->slave_detected)
 246                 rc = at91_twi_probe_slave(pdev, phy_addr, dev);
 247         else
 248                 rc = at91_twi_probe_master(pdev, phy_addr, dev);
 249         if (rc)
 250                 return rc;
 251
 252         at91_init_twi_bus(dev);
 253
 254         pm_runtime_set_autosuspend_delay(dev->dev, AUTOSUSPEND_TIMEOUT);
 255         pm_runtime_use_autosuspend(dev->dev);
 256         pm_runtime_set_active(dev->dev);
 257         pm_runtime_enable(dev->dev);
 258
 259         rc = i2c_add_numbered_adapter(&dev->adapter);
 260         if (rc) {
 261                 clk_disable_unprepare(dev->clk);
 262
 263                 pm_runtime_disable(dev->dev);
 264                 pm_runtime_set_suspended(dev->dev);
 265
 266                 return rc;
 267         }
 268
 269         dev_info(dev->dev, "AT91 i2c bus driver (hw version: %#x).\n",
 270                  at91_twi_read(dev, AT91_TWI_VER));
 271         return 0;
 272 }
 273
 274 static int at91_twi_remove(struct platform_device *pdev)
 275 {
 276         struct at91_twi_dev *dev = platform_get_drvdata(pdev);
 277
 278         i2c_del_adapter(&dev->adapter);
 279         clk_disable_unprepare(dev->clk);
 280
 281         pm_runtime_disable(dev->dev);
 282         pm_runtime_set_suspended(dev->dev);
 283
 284         return 0;
 285 }
 286
 287 #ifdef CONFIG_PM
 288
 289 static int at91_twi_runtime_suspend(struct device *dev)
 290 {
 291         struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
 292
 293         clk_disable_unprepare(twi_dev->clk);
 294
 295         pinctrl_pm_select_sleep_state(dev);
 296
 297         return 0;
 298 }
 299
 300 static int at91_twi_runtime_resume(struct device *dev)
 301 {
 302         struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
 303
 304         pinctrl_pm_select_default_state(dev);
 305
 306         return clk_prepare_enable(twi_dev->clk);
 307 }
 308
 309 static int at91_twi_suspend_noirq(struct device *dev)
 310 {
 311         if (!pm_runtime_status_suspended(dev))
 312                 at91_twi_runtime_suspend(dev);
 313
 314         return 0;
 315 }
 316
 317 static int at91_twi_resume_noirq(struct device *dev)
 318 {
 319         struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
 320         int ret;
 321
 322         if (!pm_runtime_status_suspended(dev)) {
 323                 ret = at91_twi_runtime_resume(dev);
 324                 if (ret)
 325                         return ret;
 326         }
 327
 328         pm_runtime_mark_last_busy(dev);
 329         pm_request_autosuspend(dev);
 330
 331         at91_init_twi_bus(twi_dev);
 332
 333         return 0;
 334 }
 335
 336 static const struct dev_pm_ops at91_twi_pm = {
 337         .suspend_noirq  = at91_twi_suspend_noirq,
 338         .resume_noirq   = at91_twi_resume_noirq,
 339         .runtime_suspend        = at91_twi_runtime_suspend,
 340         .runtime_resume         = at91_twi_runtime_resume,
 341 };
 342
 343 #define at91_twi_pm_ops (&at91_twi_pm)
 344 #else
 345 #define at91_twi_pm_ops NULL
 346 #endif
 347
 348 static struct platform_driver at91_twi_driver = {
 349         .probe          = at91_twi_probe,
 350         .remove         = at91_twi_remove,
 351         .id_table       = at91_twi_devtypes,
 352         .driver         = {
 353                 .name   = "at91_i2c",
 354                 .of_match_table = of_match_ptr(atmel_twi_dt_ids),
 355                 .pm     = at91_twi_pm_ops,
 356         },
 357 };
 358
 359 static int __init at91_twi_init(void)
 360 {
 361         return platform_driver_register(&at91_twi_driver);
 362 }
 363
 364 static void __exit at91_twi_exit(void)
 365 {
 366         platform_driver_unregister(&at91_twi_driver);
 367 }
 368
 369 subsys_initcall(at91_twi_init);
 370 module_exit(at91_twi_exit);
 371
 372 MODULE_AUTHOR("Nikolaus Voss <n.voss@weinmann.de>");
 373 MODULE_DESCRIPTION("I2C (TWI) driver for Atmel AT91");
 374 MODULE_LICENSE("GPL");
 375 MODULE_ALIAS("platform:at91_i2c");